Class ResolveContext

Encapsulates Depenency Injection for a path of nodes

UI-Router states are organized as a tree.
A nested state has a path of ancestors to the root of the tree.
When a state is being activated, each element in the path is wrapped as a PathNode.
A PathNode is a stateful object that holds things like parameters and resolvables for the state being activated.

The ResolveContext closes over the PathNodes, and provides DI for the last node in the path.

Methods

This adds a Resolvable (generally one created on the fly; not declared on a StateDeclaration.resolve block).
The resolvable is added to the node matching the state parameter.

These new resolvables are not automatically fetched.
The calling code should either fetch them, fetch something that depends on them,
or rely on resolvePath being called when some state is being entered.

Note: each resolvable's ResolvePolicy is merged with the state's policy, and the global default.

Given a state, this method creates a new ResolveContext from this one.
The new context starts at the first node (root) and stops at the node for the state parameter.

Why

When a transition is created, the nodes in the "To Path" are injected from a ResolveContext.
A ResolveContext closes over a path of PathNodes and processes the resolvables.
The "To State" can inject values from its own resolvables, as well as those from all its ancestor state's (node's).
This method is used to create a narrower context when injecting ancestor nodes.

example

let ABCD = new ResolveContext([A, B, C, D]);

Given a path [A, B, C, D], where A, B, C and D are nodes for states a, b, c, d:
When injecting D, D should have access to all resolvables from A, B, C, D.
However, B should only be able to access resolvables from A, B.

When resolving for the B node, first take the full "To Path" Context [A,B,C,D] and limit to the subpath [A,B].
let AB = ABCD.subcontext(a)